As it gets easier to access marijuana legally in the U.S., it’s no surprise that usage is increasing - but a new study shows the uptick also applies to pregnant women.

From 2002 until 2015 The National Survey on Drug Use and Health asked more than three hundred thousand women about their marijuana consumption in the last month, more than fourteen hundred of the participants were pregnant.

On average nonpregnant women were more likely to use the drug than expectant mothers - except in one demographic - teenagers between 12 and 17. Seventeen percent of the pregnant participants in that age group had used weed, compared to six percent of their nonpregnant peers.

“Risk-taking” behaviors may account for some of that statistic, along with misconceptions about the drug. When faced with morning sickness or body aches, pot might seem like an “all natural” approach to easing prenatal discomfort - but the American College of Obstetrics and Gynecology recommends expectant mothers avoid weed because it poses health risks to the fetus and may affect brain development in the long run.

Guest:

Allison Bond, M.D., medical writer and resident physician in internal medicine at Massachusetts General Hospital in Boston; she wrote the story about the latest study for ABC News